<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>圆角边框</title>
  <style>
    p.normal {
      border: 2px solid red;
    }

    p.round1 {
      border: 2px solid red;
      border-radius: 5px;
    }

    p.round2 {
      border: 2px solid red;
      border-radius: 8px;
    }

    p.round3 {
      border: 2px solid red;
      border-radius: 12px;
    }
  </style>
</head>
<body>
<p class="normal">普通边框</p>
<p class="round1">圆角边框</p>
<p class="round2">角更圆的边框</p>
<p class="round3">角最圆的边框</p>
</body>
</html>